Among the air conditioning systems used in office buildings and residential buildings, separate type systems having an indoor unit and an outdoor unit connected by refrigerant communication pipes are widely used. For example, in the multi separate type air conditioning system used in office buildings and other buildings, the outdoor unit is installed on the roof or other location and the indoor units are installed in the ceiling or other location of each floor, the outdoor unit and indoor units being connected together by a gas-side refrigerant communication pipe and a liquid-side refrigerant communication pipe to form a refrigerant circuit.
The outdoor unit of such an air conditioning system has a gas-side shut-off valve and a liquid-side shut-off valve, which are at the terminal ends of the part included in the outdoor unit of the refrigerant circuit. These shut-off valves are connected to the gaseous refrigerant communication pipe and liquid refrigerant communication pipe extended from the indoor units and switched from the closed state to the opened state after the outdoor unit and the indoor units have been installed onsite. As a result, refrigerant can flow between the outdoor unit and the indoor units.
Meanwhile, Japanese Patent Laid-Open Publication No. 2004-37007 shows a structure in which the gas-side shut-off valve and the liquid-side shut-off valve in a conventional outdoor unit are held in place by a mounting panel standing on the bottom frame of the outdoor unit. Although this kind of a mounting panel is not shown clearly in the drawings of Patent Japanese Patent Laid-Open Publication No. 2004-37007, often times it is shaped basically like the mounting panel 100 shown in FIG. 9. The mounting panel 100 has a shape which is formed by bending a plate-like member into an L-letter shape, and the portion 101 being bent is in surface contact with the bottom frame of the outdoor unit, while the other portion 102 has incisions 102a and 102b formed thereon for inserting the shut-off valves.